In the study, a secondary analysis of data from a randomized, controlled trial of the effects of azithromycin on the frequency of AECOPD, no relationship was found between baseline Vitamin D levels and time to first AECOPD or between vitamin D levels and AECOPD exacerbation rates.
"Vitamin D insufficiency and deficiency are common in patients with COPD, and patients with severe COPD are at the highest risk for exacerbations, so we hypothesized that low vitamin D levels might increase the risk of AECOPDs," said Ken M. Kunisaki, M.D., of the Minneapolis Veterans Affairs Medical Center. "Our negative results are in contrast with earlier studies in which lower vitamin D levels were associated withhigher rates of respiratory infections in adults and more frequent asthma exacerbations in children."In the current study, mean forced expiratory volume in one second (FEV1) was 1.12L, 40% of predicted. Mean vitamin D level at baseline was 25.7 ¡À 12.8 ng/mL, with 33.1% of subjects categorized as vitamin D insufficient (¡Ý20 ng/mLbut
During 1 year of follow-up, study subjects experienced a total of 1415 AECOPDs. Of 973 patients,360 (37%)remained AECOPD-free, 278 (29%) had 1 AECOPD, 133 (14%)had 2 AECOPDs, and 202 (21%) had 3 or moreAECOPDs.
In the primary analysis, vitamin D levels had no relationship to time to first AECOPD; for a 10 ng/mL increment in vitamin D level, the estimated hazard ratio was 1.04 (95% confidence interval: 0.97-1.12). In secondary analyses, vitamin D levels were not related to annualized rates of AECOPDs in either Poisson (p=0.82)or negative binomial analyses (p=0.87).
Patients with severe vitamin D deficiency had a higher mean rateof AECOPDs, but this difference was not statistically significant. Patients with severe vitamin D deficiency did not exhibit faster time to first AECOPD than other patients.
The study had some limitations. Vitamin D levels were only assessed at baseline, and so may have changed during the study period. Seasonal changes in vitamin D levels may also have occurred.
"Contrary to what we expected, baseline vitamin D levelswere not related to the risk of subsequent AECOPDs in this large group of COPD patients at high risk of AECOPD," Dr. Kunisaki said. "Vitamin D supplementation is unlikely to have an effect on AECOPD risk in these patients."
About the American Journal of Respiratory Research and Critical Care Medicine:
With an impact factor of 10.191, the AJRRCM is a peer-reviewed journal published by the American Thoracic Society. It aims to publish the most innovative science and the highest quality reviews, practice guidelines and statements in the pulmonary, critical care and sleep-related fields. Founded in 1905, the American Thoracic Society is the world's leading medical association dedicated to advancing pulmonary, critical care and sleep medicine. The Society's 15,000 members prevent and fight respiratory disease around the globe through research, education, patient care and advocacy.
Nathanial Dunford | EurekAlert!
Investigators may unlock mystery of how staph cells dodge the body's immune system
22.09.2017 | Cedars-Sinai Medical Center
Monitoring the heart's mitochondria to predict cardiac arrest?
21.09.2017 | Boston Children's Hospital
Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.
A warming planet
Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.
The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...
Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...
Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!
When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...
For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.
Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...
19.09.2017 | Event News
12.09.2017 | Event News
06.09.2017 | Event News
22.09.2017 | Life Sciences
22.09.2017 | Medical Engineering
22.09.2017 | Physics and Astronomy